This invention relates generally to the mixing of materials, and more particularly to a mixing well structure and process for mixing various materials with a fluid.
In numerous industrial applications materials must be fed into a pressurized environment. Such applications include coarse particle slurry transportation pipelines, solids tailings disposal systems, and feeding pulverized coal into pressurized gasification and liquification reactors.
Known prior art systems include moving mechanical parts which come in contact with the solids being transported. Such contact results in wear of the mechanical parts, requiring their periodic replacement. Such known equipment is massive in size, costly to manufacture and repair, and generally operates in a batch rather than a continuous mode.
One known type of prior art device includes a massive rotating valve which periodically delivers discreet batches of solids to a mixing region where the solids are mixed with a fluid, such as compressed air or another gas, or water or another liquid. Another known type of prior art device advances solid materials along a twinscrew extruder to a mixing region. In each such prior art system, a mechanical device in physical contact with the solids is used to transport the solids. Friction developed between the mechanical transporting device, generically referred to hereinafter as a pump, and the solids to be transported, produces wear of pump members. Such wear requires not only costly maintenance, but results in contaminating the transported solids with the material worn-off the pump members.
Thus, there is a need for mixing well structure having no moving mechanical parts, having no pump members in physical contact with the solids being transported, and which is continuous in operation, and relatively inexpensive to manufacture and maintain.